Blog of AMEG, the Arctic Methane Emergency Group, discussing the situation in the Arctic and the action necessary to avoid catastrophic warming, including the need for geoengineering to be accepted as an indispensable part of a comprehensive plan of action to cool the Arctic and to bring the atmosphere and oceans back to their pre-industrial state.

Monday, May 14, 2012

We are starting our first post on this blog by presenting what we consider the overwhelming scientific evidence of a planetary emergency arising from a combination of: (i) the warming of the Arctic, (ii) the rapid melting away of Arctic sea ice, (iii) the releasing into the atmosphere of ever larger quantities of the potent greenhouse gas, methane, from thawing structures, and (iv) positive feedback between these three processes.

Figure 1. The huge temperature rise in the Arctic (latitudes 60 North to North Pole), compared to temperatures at lower latitudes (surface air temperatures as nine-year running means relative to the 1880–1890 mean).

Figure 3. The striking rise of methane in the Arctic (click on image to enlarge)

Figure 4. Global emissions cause warming, especially in the Arctic, where warming is further accelerated by feedbacks, in particular sea ice loss and methane releases, threatening to lead to runaway global warming.

We argue that the response to this emergency should be concerted international action, taking measures to cool the Arctic which would include geoengineering of a kind known as “solar radiation management” (SRM) [1]. These measures should be taken as quickly as conceivably possible in order to reduce the risk of passing a point of no return – a point beyond which the whole climate system would tip, inevitably, irreversibly and inexorably, into such a hot state as to threaten the survival of civilisation.

This is the situation in a nutshell:

the Arctic is warming rapidly – much faster than global warming;

the sea ice volume is plummeting;

a collapse in sea ice extent is likely by 2015;

a collapse in sea ice means loss of habitat and biodiversity, risking the breakdown of an important marine food chain;

a collapse in sea ice also means faster warming of the Arctic, creating more climate disruption and weather extremes in the Northern Hemisphere.

This is bad enough. Add to this the menace of Arctic methane. Consider that:

methane’s potency as a greenhouse gas is about 105x that of CO2 over 20 years, weight for weight [2];

there’s a vast quantity of methane frozen into Arctic seabed [3];

loss of sea ice cover allows storms to mix the warmed surface water with colder water beneath, causing shallow seabed to warm, thawing out methane-holding structures;

because of warming and instabilities in the seabed, large quantities of methane could be released quite rapidly – enough to drastically exacerbate global warming [4];

methane bubbles have now been observed in huge plumes, over 1km across, in shallow sea [5], suggesting an escalation of methane emissions could be happening already, even without further warming of the Arctic;

Arctic methane may be contributing to rising global levels of methane in the atmosphere [6].

The worst fear is that methane could build up in the atmosphere sufficiently to start a runaway cycle of greenhouse warming and more methane release, leading to abrupt and catastrophic climate change.

The only way to prevent a chain of events which could lead to such a runaway cycle is to cool the Arctic, save the sea ice and dampen methane emissions. To minimise risk, we need to use all possible means.